Cholesterol is a waxy, fat-like type of lipid produced by the body's cells and found in the blood. It is an essential substance for vital functions such as hormone production, digestion, and cell membrane formation. It also plays an important role in Vitamin D synthesis. The human body produces approximately three-quarters of its daily cholesterol needs internally. The main center for this production is the liver, which provides about 70% of daily cholesterol. The remaining production occurs in the adrenal glands, small intestine, and reproductive organs. Approximately one-quarter of cholesterol needs are obtained from animal products such as egg yolks, cheese, and meat. Cholesterol, which ensures the durability of cells, is critically important not only for health but also for life itself. Reproductive processes are also made possible through cholesterol; indeed, steroid hormones like testosterone and estrogen cannot be produced without cholesterol.